Bipolar Risk Fourfold Higher When Pregnant Mother Exposed To Flu

Research has found long-term disorders in adulthood may begin at pregnancy. A National Institutes of Health (NIH) funded study has found pregnant women who come in contact with influenza increase the risk their child will later develop bipolar disorder by fourfold. Other studies have also found that a pregnant woman´s exposure to the flu may lead to the child´s development of schizophrenia. The doctors who conducted this research are once again urging women to take extra precautions when they become pregnant.

“Prospective mothers should take common sense preventive measures, such as getting flu shots prior to and in the early stages of pregnancy and avoiding contact with people who are symptomatic,” said Alan Brown of Columbia University and New York State Psychiatric Institute in a statement.

“In spite of public health recommendations, only a relatively small fraction of such women get immunized. The weight of evidence now suggests that benefits of the vaccine likely outweigh any possible risk to the mother or newborn.”

Though this study is not the first to suggest a link between influenza and bipolar disorder, it is the first to follow families from the same HMO to obtain their data. Using diagnoses from the families´ physicians and standard psychiatric practices, Brown and his team had access to more flu exposure information than any previous study.

Among a group of children born in one northern California County between 1959 and 1966, 92 had developed bipolar disorder. The researchers then matched this data with material flu rates in the county at the same time. This data implies a connection between rising flu rates and bipolar disorder, a connection which became stronger when the woman was exposed to the flu late in her pregnancy. What´s more, the researchers found that flu exposure can cause a sixfold increase in the risk of the child developing a subtype of bipolar disorder with psychotic features.

Brown has performed this kind of study before. After researching data from a “related” northern California County, the team found exposure to the flu resulted in a threefold increase in risk for developing schizophrenia. Other research has also linked viral infections early in the pregnancy to autism.

“Future research might investigate whether this same environmental risk factor might give rise to different disorders, depending on how the timing of the prenatal insult affects the developing fetal brain,” said Brown.

According to Brown, bipolar disorder and schizophrenia share some overlap, both in suspected causes and features. For instance, both of these illnesses become evident in early adulthood and have been found to be hereditary. The overlap between these two illnesses and other disorders has led the National Institute of Mental Health (NIMH) to begin a new project responsible for classifying new mental disorders. With these new classifications in place, the NIMH hopes to avoid any missed diagnoses when one disorder closely resembles another.